Learning to Composite

One of the first projects this trimester is to re-create a game trailer for an older game to freshen it up to as new audience. To help my group in achieving this I put my hand up to handle the composite and VFX work for the trailer as I haven’t really had the opportunity to get my hands dirty in this type of work yet. So to give myself a little kick-start I decided to pay a visit to the best tutorial site I know of, DigitalTutors and as usual I wasn’t dissappointed. I found a project that involved bringing many different elements into a single scene and using the various composite techniques, make it all look like it belonged.

Starting with a blank background of a camera panning a suburban street, I brought in the main character, a sci-fi robot that does a forward roll bringing his gun arm up to the camera. It was interesting to find out all these little details that you never even know of during the editing phase that truly makes it a colossal effort to make modern day movie look as good as they do. I say this because as soon as I brought in the robot I pressed play and immediately noticed a problem. Because the camera is panning across the background, the robot whilst it rolls forward it is also magically sliding across the ground defying physics. This is when I learnt about tracking mechanics, and by setting a anchor point to where you want the object to stick to in reference to camera movement, you can have the desired object perfectly track realistically in the scene and the audience will be none the wiser. This tracking effect was also applied to every piece of rubble, the helicopter, the flames and even the special effects flare on the robots gun.

Keeping the project clean and tidy I used precompositions which were really handy as they still allowed me to make edits with the layers whilst making the project windows easier to navigate. Essentially precomps, are nested compositions, so when you are editing a composition adding multiple effects and filters etc, you can then grab all of these layers and turn them into a precomp which converts them all into a single layer. However if you need to still make changes you can simple double click the precomp and it will open it up with all the layers its made up of for you to continue editing. Nifty little system.

Placing a layer with all its attributes into a Pre-Composition.The precomp which has hidden the attributes cleaning up the project window.

Following precomps, I began to tidy up the scene with a bunch of masking in order to blend the elements into the scene better, but masking is a simple process so I won’t go into detail about it. However, no matter how much feathered masking there is all the elements won’t look like they belong into the scene until the various colour correction and cinematography techniques are applied and I must admit there was a lot used in this project. Colour correction simply adjust the entire scenes colour mood into one unifying colour that serves to not only make the various assets look like they belong but to also set the mood of the scene. For this sci-fi scene I decided to give it a slightly blue tinge to reinforce the mechanical sci-fi-ish content. I then added depth of field and motion blurs to further accentuate the various moving elements in the scene. Lastly to finish the

Chromatic Aberration

project off I added some simple effects to make it seem like it was shot with a traditional camera. The first was a vignette which is the slightly darker blurred corners of the image which replicates how the camera reacts to incoming light. Secondly I added filter-flare ghosting which takes the brightest parts of the scene and mirrors and inverts the parts to replicate how UV filters act on a camera lens. Then lastly to replicate chromatic aberration which happens when the light waves don’t match up, you’ll see an offset of the blue and red channels. Similar the the old school 3D glasses how you would see multiple colours around the edges of objects.

It was really interesting learning about the various details that go into making a scene look believable and in the end all those little details really made this simple scene come to life in a J.J.Abrams sort’ve way. I feel a lot more confident when it comes to compositing the game trailer although I wonder how these effects will apply to a 2.5D scene.